A number of plant-derived lung toxins contain the furan moiety, as do those found in commerce and industry. Some of these compounds also damage liver and/or kidney. This project incorporates the study of a number of simple heterocycles; toxicity to lung, liver, and kidney will be measured, as will distribution to other parts of the body and metabolism of the materials. It is hoped that these studies will enable toxicologists to predict the organ(s) likely to be attacked by a given compound, and reveal something of the chemical mechanisms involved in such injury.